Trillium 240 OBS User Guide
Contents
1. EA Trillium 240 OBS User Guide 2005 2006 Nanometrics Inc All Rights Reserved Trillium 240 OBS User Guide The information in this document has been carefully reviewed and is believed to be reliable Nanometrics Inc reserves the right to make changes at any time without notice to improve the reliability and function of the product No part of this publication may be reproduced stored in a retrieval system or transmitted in any form or by any means electronic mechanical photocopying recording or otherwise without the prior written permis sion of Nanometrics Inc Nanometrics Inc 250 Herzberg Road Kanata Ontario Canada K2K 2A1 Tel 613 592 6776 Fax 613 592 5929 Email info 9 nanometrics ca www nanometrics ca Part number 15857R2 Release date 2006 02 08 Contents PIQUIOSs 6 wesen ee ar o tg V D HTTP m vii INtrOdUelION n 08175 betta dc o dore be er hte ot 1 Installation gt ssc ee arreter tum xn pu Save Ere Ox X dete qd ene a eases 9 Unpacking thie Sensor i23 eee eben re ede deta edad E erba 3 Installing the Sensor venom Ee Fa VERE VEN exon bia I SE Rd tpa Ei 3 Installing the sensor cable sisse m dmg a Rn 3 Mass centring sa eerte nere H R pes og wal BAGUE ad 4 Tilttolerarice x 2 22 2422 aate aru eat repre at erstens 4 Mechanical mass centring llle rn 4 Choosing when to initiate mass centring llle 4 How to initiate mass cent2. 2 3 Installing the sensor cable 1 Connect the sensor cable The cable should be strain relieved at some point close to the sensor for example with tie wraps and tie wrap anchors Ensure that the cable does not interfere with either the levelling mechanism or the sensor measure ments for example by impinging on the sensor case 2 Ensure that the digitizer case is solidly earthed and that the outer shield of the cable and the sensor case are thereby earthed 15857R2 Trillium 240 OBS 3 2006 02 08 User Guide Chapter 2 Installation 2 4 Mass centring The Trillium 240 OBS has an automated mechanical mass centring capability that uses a precision stepper motor to centre the boom of the pendulum of each axis exactly at the null point The motor adjusts the tension on the spring which supports the boom to compensate both for tilt from absolute level and for the ambient temperature in which the unit is operating As well the sensor automatically recentres the masses electronically to compensate for gradual changes in temperature up to a range of 10 C difference from when mechan ical mass centring was last initiated 2 4 1 Tilt tolerance The Trillium 240 OBS can be mass centred if the sensor is within 1 0 of level although it is good practice to ensure the sensor is levelled as precisely as possible before centring the masses Once the Trillium 240 OBS has been precisely mass cen tred that is the mass position voltage
3. 73 332 342 15857R2 Trillium 240 OBS 1 1 2006 02 08 User Guide Chapter 3 Operation Figure 3 3 Trillium 240 OBS self noise PSD dB wrt 1 m7 s4 Hz 100 ae y NLNM POR 10H NHNM MLNM p INL A 420 L Trillium 240 Pal wd Er w o A gt o EN e o x D oO 190 mnn MARA onsen 200 7 TI i RT TC 10 10 10 10 10 Frequency Hz To determine the dynamic range at frequencies of interest for your application com pare the noise floor to the sensor clip level using Figure 3 4 In this figure for compar ison of noise floors to clip levels we convert power spectral densities using octave bandwidths and an RMS to peak conversion factor of 1 253 12 Trillium 240 OBS User Guide 15857R2 2006 02 08 Chapter 3 Operation Figure 3 4 Trillium 240 OBS performance 20 NLNM NHNM MLNM M1 5 at 10 km 40 M3 5 at 10 km M5 5 at 10 km M1 5 at 100 km M3 5 at 100 km 60 M5 5 at 100 km M7 at 100 km M6 at 3000 km M8 at 3000 km 80 Trillium 240 Self Noise Trillium 240 Clip Level Dig Noise Max Gain Dig Noise Min Gain Dig Clip Max Gain 100 Dig Clip Min Gain 120 140 160 Peak Velocity in Octave Bandwidth dB wrt 1 nf s 180 200 220 10 Frequency Hz 3 7 Calibration Calibration inputs are provided to allow for relative calibration of the sensor across fre quency and over time Since the Trillium 240 OBS
4. UVW TX U_CALEN V_CALEN and W_CALEN All of these inputs are optically isolated from both the input voltage and the output and calibration input signals Therefore signals applied to these pins must be referenced to DGND rather than PWR or AGND All of these inputs are active high Specifically any voltage greater than 3 5 V at a cur rent greater than 0 1 mA enables the relevant functionality while any voltage less than 1V ora high impedance disables it All inputs can tolerate at least 15 V except for UVW TX which can tolerate voltages from 7 V to 15V 3 4 Output signals The sensitivity specified in Table 3 2 on page 10 assumes an infinite input impedance at the digitizer For digitizers with low input impedance it will become necessary to account for the fact that source impedance of the differential outputs is 300Q 1 150Q each output A control signal switches the Trillium 240 OBS output signal to either UVW output or XYZ output The natural sensor output is UVW in this mode the outputs represent the actual motion of the masses of the three sensor components The conventional sensor output is XYZ in this mode the outputs represent horizontal and vertical motion See Table 3 1 for the polarities of the XYZ outputs and their correspondence to the directions of the compass Table 3 1 Axis orientation and polarity of XYZ outputs Axis Orientation Positive voltage represents X east west case motio
5. referenced to DGND Issue a Center command using the RS 232 digital interface see Section 3 9 on page 14 2 4 3 Continuous electronic mass recentring 2 4 3 1 Continuous electronic mass recentring compensates for gradual changes in tempera ture up to a range of 10 C difference from when mechanical mass centring was last initiated If the temperature changes more than 10 C the unit may need to be mechan ically mass centred Mass recentring status The mass position status is reported via analog signals U MP V MP and W MP ref erenced to AGND pins E F S and V respectively which operate roughly in the range 4V A OV signal means the axis boom is perfectly centred A signal exceeding 2 V indicates mechanical mass recentring should be initiated These signals respond very slowly to changes in tilt mass position or temperature when the sensor is in the normal operating long period mode but respond almost instantly within a second when the sensor is set to short period mode The mass position status is also reported digitally via the RS 232 serial interface see Section 3 9 on page 14 2 4 4 Mass centring procedure When using a Nanometrics digitizer such as a Taurus or Trident that is connected to a network you can read the mass position status and initiate mass centring remotely For the Taurus use options in the Sensor page either locally or on an external browser The Taurus also provides a mass auto cen
6. 02 08 Trillium 240 OBS Mounting Pedestal The Trillium 240 OBS Mounting Pedestal is a jig that you can use to mount the Trillium 240 OBS for land based testing and setup The Pedestal includes levelling feet a lev elling bubble and North South East West alignment indicators E 1 Installing the Pedestal 1 Turn the Trillium 240 OBS upside down onto something that will not scratch the painted surface of the cover Brace the Trillium 240 OBS to ensure that it will not roll off the work space Align the three Pedestal standoffs to the unpainted pads on the Trillium 240 OBS base The Pedestal is positioned correctly if the Pedestal cable connector is on the same side as the connector on the base of the Trillium 240 OBS Figure E 1 on page 29 Carefully lower the Pedestal onto the Trillium 240 OBS base Align the holes and thread the 3 supplied M6 screws through the Pedestal into the holes in the Trillium 240 OBS base Hold the Trillium 240 OBS firmly and torque each of the 3 Pedestal screws to 50 inch pounds If these screws are not tightened properly the Trillium 240 OBS performance may be affected Connect the cable connector to the Trillium 240 OBS connector Set the Trillium 240 OBS Pedestal assembly in the desired location before you level the assembly gt All three levelling feet must rest directly on the installation surface gt If you need to align the Trillium 240 OBS draw a line on the installation sur face to tru
7. User Menu Version 3 30 Program A KKK KK KKK KKK ck Ck ck KK KKK KKK KK KKK KKK KKK KH KK AH KH RK TH TH ko KK KH KT AH KK KH TH KH KH AH ck KK k KH KK A HK AH KKK Help Repeat this menu also turns on Serial TX Tx Enable the Serial Transmit Signal TxOff Disable the Serial Transmit Signal Upload Upload software to the alternate program Switch Switch to the alternate program Default Set the current program as default Reboot Reboot the instrument GetInfo Get factory configuration information ReadFC Read factory calibration parameters WriteUC Write user calibration parameters ReadUC Read the user calibration parameters Soh Report state of health ShortPer Set sensor to short period mode LongPer Set sensor to long period mode SetXYZ Set sensor to XYZ mode SetUVW Set sensor to UVW mode Center Center all masses or u v w CheckSum Print checksum value for both program A and B CK ck ck ck ck ck Sk ck kk ck Ck ck ck KKK KKK ck ck ck KKK KKK ck ck KKK KKK ck ck ck ck kk ck kk kk ck kk kk ck ko kc kk ko ko ko ko A KH AH A I U Please type a command and hit return Each of the serial port commands is described in Table 3 3 Table 3 3 Serial port commands Command Description Help Repeat this menu also turns on Serial TX Use the He1p command to view the list of commands The first line identifies the firmware version in use and whether it is Program A or Pro
8. is a symmetric triaxial sensor calibration must be per formed on the individual sensor axes UVW rather than the horizontal and vertical out puts XYZ Individual axis outputs can be digitized by placing the sensor in UVW mode see Section 3 4 15857R2 2006 02 08 Trillium 240 OBS 1 3 User Guide Chapter 3 Operation Each axis has a separate calibration enable signal U_CALEN V_CALEN W_CALEN All axes use a common calibration input signal CAL SIG which has a sensitivity of 0 010 m s V 3 8 State of Health Mass position output signals U MP V MP and W MP are provided to monitor the effect of tilt and temperature on the spring which sets the rest position of the boom As with the calibration signals they represent the state of the individual sensor axes UVW rather than the horizontal and vertical outputs XYZ The mass positions are zeroed by initiating the automatic mass centring feature which uses stepper motors to precisely tension the spring See Section 2 4 on page 4 for a discussion of these sig nals If the mass positions are all within the range 0 3 V then there is no need for recentring Otherwise follow the procedure in Section 2 4 4 Mass centring procedure on page 5 3 9 Connecting and configuring the serial port 1 Connect an appropriate RS 232 communications device such as a PC serial port to the sensor by connecting its TX pin to the MC RX signal pin C and its RX pin to the UVW TX sig
9. is within the range 0 3 V the sensor can tol erate a shift of up to 0 03 without mass recentring being required 2 4 2 Mechanical mass centring The operation of mass centring typically takes less than 1 minute It may take up to 5 minutes if the unit is compensating for substantially different tilt than it had when it was last centred 2 4 2 1 Choosing when to initiate mass centring While mass centring can be done immediately after installing and levelling the Trillium 240 OBS it is best to initiate mass centring again at least 6 hours after installation when the temperature has fully equalized This ensures the unit will then be able to tolerate up to 10 C range variation in ambient temperature with out requiring recentring It is best to initiate mechanical mass centring when the ambient temperature is roughly in the centre of its expected range rather that at one extreme or the other to make the most of the usable 20 C range the unit can tolerate without mechani cal recentring Mass centring should only be done when interruption of good quality seismic data can be tolerated as there are temporary effects on the output signal When the mass centring motors are operating the sensor transfer function is set to a short period mode and the motion of the boom during the recentring is very evident in the output signal When the mass centring operation is complete the sensor reverts to the mode it was in before mass c
10. LL DRAIN 6 P1 E U MP P2 EXT SOH3 ORG 7 P1 AGND P1 CH1GND BLK 7 P1 SHELL P2 SHELL DRAIN 7 P1 PWR P2 SEN 12V RED 8 P1 G PWR P2 SENRTN WHT 8 P1 SHELL P2 SHELL DRAIN 8 P1 D UVWITX P2 CTRL1 RED 9 P1 MC RX P2 CTRL2 GRN 9 P1 R DGND P2 DGND DRAIN 9 P1 SHELL P2 SHELL BRAID 24 Trillium 240 OBS User Guide 15857R2 2006 02 08 Cable Design Sensor cable design guidelines K Sensor cables should be designed for good EMI shielding This is most easily accomplished using double shielded twisted pair cable The twisted pairs provide magnetic shielding an inner shield grounded at the digitizer provides good electric field shielding and a continuous outer shield provides good high frequency RF shielding gt The outer shield should be earthed at the digitizer for safety gt The digital ground DGND must be used for the return currents of the control sig nals U_CALEN V_CALEN W_CALEN UVW TX and MC RX K The analog ground AGND must be used for the return currents of the analog sig nals CAL_SIG U_MP V_MP and W_MP K Note that AGND is connected to chassis ground CHGND inside the Trillium 240 OBS so if these signals are already connected at the digitizer AGND should not be connected through the cable or else a ground loop will be created See Appendix B for the connector pinout 15857R2 Trillium 240 OBS 25 2006 02 08 User Guide Appendix D Cable Design 2 Trillium 240 OBS 15857R2 User Guide 2006
11. X output 5V input initiate mass centring as MC input active high 5 to C MC RX input serial RS 232 receive 15V low open or OV as RX input 5 V OV to 15V R DGND digital ground N A shell CHASSIS for shielding and safety N A 15857R2 Trillium 240 OBS 21 2006 02 08 User Guide Appendix B Connector Pinout 22 Trillium 240 OBS 15857R2 User Guide 2006 02 08 Generic Sensor Cable A generic sensor cable may have been shipped with your sensor Table C 1 on page 24 is the wiring key for the standard cable Nanometrics part number CBL13942R2 This table can be used as a reference when wiring the generic sensor cable end to a digitizer connector 15857R2 Trillium 240 OBS 23 2006 02 08 User Guide Appendix C Generic Sensor Cable Table C 1 Generic sensor cable wiring for CBL13942R2 From To Wire Run Conn Pin Name Conn Pin Name Colour P1 L Z W P2 CH1 RED 1 P1 M Z IW P2 CH1 BLK 1 P1 P2 CH1GND DRAIN 1 P1 Y NV P2 CH2 WHT 2 P1 A Y V P2 CH2 BLK 2 P1 P2 CH2GND DRAIN 2 P1 P X U P2 CH3 GRN 3 P1 B X U P2 CH3 BLK 3 P1 P2 CH3GND DRAIN 3 P1 T CAL SIG P2 CAL1 BLU 4 P1 U W_CALEN P2 CAL1 CTRL4 BLK 4 P1 SHELL P2 SHELL DRAIN 4 P1 J V_CALEN P2 CAL2 CTRL5 YEL 5 P1 K U_CALEN P2 CAL3 CTRL6 BLK 5 P1 SHELL P2 SHELL DRAIN 5 P1 S W MP P2 EXT SOH1 BRN 6 P1 V MP P2 EXT SOH2 BLK 6 P1 SHELL P2 SHE
12. c lt Manufacture gt lt Product gt Trillium Firmware lt Product gt lt Version gt 3 30 lt Version gt lt Temperature gt 26 22 lt Temperature gt lt Mass gt U 0 030 V 0 497 W 0 063 lt Mass gt lt Adc gt U 14 V 225 W 29 lt Adc gt lt Modes gt Period Long Channel XYZ lt Modes gt lt Positions gt U 380 V 66 W 110 lt Positions gt lt Zeros gt U 0 V 0 W 0 lt Zeros gt lt Range gt U 7043 V 7371 W 7151 lt Range gt lt SOH gt lt Version gt The version of the firmware that is currently running Temperature The temperature near the main electronics PCB which is located in a chamber near the top of the unit The temperature of the axes will likely be different from this The mass positions for each axis U V W These are reported in two forms Mass decimal numbers with a 4 2 range that roughly corresponds to the output voltage at the U_MP V_MP and W_MP signals lt ADC gt proportional integer numbers with a range of 1900 The lt ADC gt number is about 452 times the lt Mass gt decimal number Modes The sensor modes are reported including whether the sensor is in long period or short period mode and whether the seismic signals are output in XYZ or UVW mode The lt Range gt lt Positions gt and lt Zeros gt numbers pertain to the mass recentring stepper motors The Range number is the full range in steps the mass positioning stepper motor can traverse between the two o
13. e North or true East and use the North South or East West lines on the Pedestal If you are using a magnetic compass account for the local mag netic declination when drawing the line 15857R2 2006 02 08 Trillium 240 OBS User Guide 27 Appendix E Trillium 240 OBS Mounting Pedestal E 2 Levelling the assembly To level the Trillium 240 OBS Pedestal assembly use the three adjustable height feet with lock nuts and the levelling bubble on the Pedestal 1 Ensure that all three levelling feet are resting directly on the installation surface 2 Unlock the feet as required to level the assembly and then lock them again by threading the lock nut up until it engages firmly with the Pedestal Note that the locknut has a mechanical stop that prevents it from loosening more than a third of a turn It may be necessary to hold the body of the levelling foot still while locking the nut to avoid disturbing the levelness of the sensor K Extend the levelling feet as little as possible to achieve a level sensor Keep at least one of the feet two if possible retracted fully into the Pedestal 3 After aligning the Trillium 240 OBS Pedestal assembly to a compass direction the assembly may need to be relevelled due to unevenness in the installation surface While the Trillium 240 OBS will operate properly with the bubble anywhere inside the black ring on the level the bubble should be centred as precisely as pos sible to ensure the Z output i
14. e peak power surge may be up to 4 5 W briefly Power consumption above normal quiescent after the initial power on in rush is roughly proportional to the output signal If the sensor is not centred or has not yet settled the output signals will be at the maximum and power consumption may be as high as 3 W For a settled centred and level sensor a seismic signal that approaches the sensor s maximum clip level may draw as much as 2 W peak the average power consumption would be much lower The mass centring operation will draw additional power up to an incremental 2W while the motors are operating For long cables be sure to account for the resistive voltage drop due to the cable itself For example 50m of 24 AWG wire has a resistance of 4 2Q in each direc tion Therefore the voltage drop due to the possible 500mA startup in rush at 9V would be 4 2 V and the power supply must be able to briefly supply 13 2 V for this length of cable The supply should also be able to sustain a 2W peak output at a voltage that guarantees the sensor receives 9 V For the 50m cable example the peak current would be 220mA at 9 V and the voltage drop would be 1 9 V so the supply must be able to provide 220mA at 10 9 V to reliably power the sensor for maximum seismic signals when using a 50m cable 15857R2 2006 02 08 Trillium 240 OBS 7 User Guide Chapter 3 Operation 3 3 Control signals Trillium 240 OBS has 5 digital control inputs MC RX
15. ely seismic data may be digitized with the Trillium 240 OBS in UVW mode and the transformation to horizontal and vertical signals implemented optionally when the data are processed This allows for studies and calibrations where both UVW and XYZ data are required 15857R2 Trillium 240 OBS 9 2006 02 08 User Guide Chapter 3 Operation 3 5 Frequency response The frequency response of the Trillium 240 OBS can be measured using the calibration coil The measured response is the product of the calibration system s first order low pass response and the sensor s own response The nominal Trillium 240 OBS response is obtained by dividing the nominal sensor calibration result by the calibration system s transfer function the three frequency response functions are shown in Figure 3 2 The calibration system s low pass response cancels the zero at 161 rad s in the sensor transfer function when the sensor frequency response is measured using the calibration coil The nominal poles p zeroes z normalization factor k and normalization fre quency of the Trillium 240 OBS are shown in Table 3 2 These parameters define the transfer function according to this equation LI T F s S A 6 L sensor EQ 3 m The normalization factor is defined according to this equation 1 k EQ 4 2 2 fot zn A J C 2 fot Pr n Table 3 2 Poles and zeroes Parameter Nomina
16. entring was initiated generally long period mode At this time there may be a transient superimposed on the output signal that takes some minutes to decay To determine whether mass centring needs to be done you can check the voltage readings on the mass position outputs for each of the three sensor channels signals U_MP V_MP and W_MP referenced to AGND e Ifthe values are outside the range 3 5 V the sensor may not be able to report seismic signals properly For this condition mass centring must be done A Trillium 240 OBS 15857R2 User Guide 2006 02 08 Chapter 2 Installation e Ifthe values are within the range 3 5 V but not within the range 2 V the sen sor is sufficiently centred that it will report seismic signals properly However it is strongly recommended the masses be recentred e Ifthe values are within the range 2 V but not within the range 0 3 V the sen sor is sufficiently centred that it will report seismic signals properly However the closer the mass positions are to 0 V the more room there is to tolerate fur ther ambient temperature changes For this condition centring the masses is recommended if it is convenient to do so e Ifthe mass positions are all within the range 0 3 V there is no need to recentre although it can be done if desired 2 4 2 2 How to initiate mass centring You can initiate mass centring using either of these two methods K Pull the MC RX pin high for at least 1 second
17. ew seconds to at most 5 minutes but is typically less than 1 minute 4 Observe the voltage readings on the mass position outputs to confirm they are now within the 0 3V range Note that the sensor is temporarily put into short period mode during the cen tring operation and the previous mode is automatically restored when the centring operation is complete 2 5 Installation checklist U Sensor serial number is noted LL cable is connected to the sensor and the digitizer U Cable is strain relieved close to the sensor LL cable will not impinge on the sensor case after levelling U Masses are centred after temperature equalization at least 6 hours post installation 6 Trillium 240 OBS 15857R2 User Guide 2006 02 08 Operation This chapter provides operating parameters and instructions for the Trillium 240 OBS 3 1 External connector The Trillium 240 OBS connector is a 19 pin male military circular type hermetic con nector The pinout is given in Appendix B 3 2 Sensor power The Trillium 240 OBS can be powered using a DC source that can sustain 9V to 36V at the sensor connector Voltage drops over the cable must be accounted for and so the supply voltage at the source may need to be higher In normal operation the sensor is level and well centred there is a low seismic signal the sensor has settled for at least 30 minutes and serial transmit is disabled the power consumption is typically 650mW On startup th
18. gram B The Help command also turns on the TX signal if it has not already been turned on after a delay of 3 seconds It is the only command besides Tx that will enable the sensor s serial transmit signal Tx Enable the Serial The Tx command turns on the sensor s serial transmit signal signal Transmit Signal UVW TX pin D after a delay of 3 seconds and sends the message Serial Transmit Enabled lt LF gt lt CR gt The serial transmit port stays enabled until turned off by the Txo command or by cycling the power to the sensor In this mode the UVW TX pin must not be used as an input pin for UVW mode TxOff Disable the The TxOff command turns off the sensor s serial transmit signal signal Serial Transmit Signal UVW TX pin D and then waits 3 seconds After the 3 second delay this pin will be interpreted as the UVW mode input pin Upload Upload soft Caution Please DO NOT use the Upload command unless ware to the alternat specifically directed by Nanometrics Technical Sup program port as it erases the firmware in the alternate parti tion The Upload command uploads a new version of firmware to the firmware partition A or B that is not currently running 15857R2 Trillium 240 OBS 2006 02 08 15 User Guide Chapter 3 Operation Table 3 3 Serial port commands Continued Command Description Switch Switch to the alternate program There are two instances of firmwa
19. he other axes for example Center V centres the V axis only CheckSum Print check sum values for both program A and B Use the Checksum command to check the firmware checksums of both partitions and what they should be This is useful to ensure there is valid code in each partition for example before switching to the alternate firmware partition 3 10 Troubleshooting and maintenance The Trillium 240 OBS mechanical and electronic elements have been designed to be robust and reliable to ensure there is no need to open units for on site maintenance The internal reverse voltage protection and over current protection automatically resets when the fault is removed so there are no fuses to replace The automatic mass ten sioner mechanism is designed to be jam proof In the unlikely event the sensor does not operate correctly please contact Nanometrics support see Chapter 1 Introduction 1 Trillium 240 OBS User Guide 15857R2 2006 02 08 Specifications This section lists the specifications of the Trillium 240 OBS A 1 Technology Topology Symmetric triaxial Feedback Coil magnet force feedback with capacitive transducer Mass centring Automatic mechanical recentring can be remotely initiated Levelling Optional Trillium 240 OBS Mounting Pedestal includes integrated bubble level and adjustable locking levelling feet A 2 Performance Self noise See Figure 3 3 o
20. ignment and Mounting Features naaa 31 Figures 1 1 3 1 3 2 3 3 3 4 E 1 F 1 Trillium 240 OBS shown with optional Mounting Pedestal 1 Sensor axis orientations 000 ee 9 Nominal frequency response 2000 c eee tees 11 Trillium 240 OBS self noise 0 0000 12 Trillium 240 OBS performance ananasa naaa 13 Mounting the Trillium 240 OBS on the Pedestal 0 0 00 seen een 29 Alignment and mounting features l l 32 Figures vi Tables 2 1 Mass position output voltage indicating need for mass centring 6 3 1 Axis orientation and polarity of XYZ outputs snaa anaana aaae 8 3 2 Poles and Zeroes 1 4414 debe vigade bt vad d eite ess vp e pid tees 10 3 3 Serial port commandS sanana aaae 15 B 1 Connector pinout o 21 C 1 Generic sensor cable wiring for CBL1I3942R2 2 2 ee 24 yii Tables viii Chapter 1 Introduction Trillium Model 240 OBS is a three component very broadband low noise seismome ter designed for deployment in a suitable ocean bottom seismograph system Its extended low frequency range useful out to beyond 1000 seconds low noise and wide dynamic range make it ideal for teleseismic studies as well as for regional and local events Figure 1 1 Trillium 240 OBS shown with optional Mounting Pedestal The Trillium 240 OBS has an internal automated mass centring ca
21. ing the connector Weight 9 5kg Parasitic resonances None below 130Hz A 6 Environmental Operating temperature 20 C to 50 C Storage temperature 40 C to 70 C Pressure Designed to be operated at standard atmospheric pressure Humidity 0 to 100 Shock 20g half sine 5ms without damage 6 axes No mass lock required for transport Weather resistance Rated to IP68 and NEMA 6P for outdoor use dust and immersion resistance 2 Trillium 240 OBS User Guide 15857R2 2006 02 08 Connector Pinout The Trillium 240 OBS connector is a 19 pin male military circular type hermetic con nector The pinout is given in Table B 1 Table B 1 Connector pinout Pin Name Function Type L Z W vertical W axis output M Z IW N Y V north south V axis output 40V peak to peak differential A Y N P X U east west U axis output B X U y y 9 2kQ input impedance T CAL_SIG calibration signal input 2 0 010 m s V nominal K U CALEN J V CALEN calibration enable inputs active high EEN low open or 0V U W_CALEN E U_MP F V_MP mass position outputs 4 5V single ended S W_MP V AGND analog ground N A H PWR power input 9V to 36V DC isolated G PWR power return input enable UVW instead of XYZ as UVW input active high 5 D UVW TX outputs to 15V low open or OV output serial RS 232 transmit as T
22. instrument Use the Reboot command to restart the firmware GetInfo Get factory configuration informa tion ReadFC Read factory calibration parameters Use the commands Get Info and ReadFC to read factory information stored in the Trillium 240 OBS Factory configuration information includes model version and serial numbers and other factory information for the unit axes and various circuit boards in the sensor This information is primarily used by Nanometrics Technical Support Factory calibration parameters may include information regarding measured sensitivity transfer function and the like WriteUC Write user calibration parameters Use the command Writeuc to upload calibration information from a text file in Turtle format You can use ReadFc to view the factory calibration information for an example of the syntax For information on Turtle see http www ilrt bris ac uk discovery 2004 01 turtle For information on RDF in general see http www w3 org RDF ReadUC Read the user calibration parameters Use the ReadUC command to display calibration information stored using the WriteUC command 1 Trillium 240 OBS User Guide 15857R2 2006 02 08 Chapter 3 Operation Table 3 3 Serial port commands Continued Command Description Soh Report state of Use the soH command to view state of health information as listed below health lt SOH gt lt Manufacture gt Nanometrics In
23. knowledgeable person for reply Before returning a unit for repair contact Nanometrics Support to obtain an RMA number Email support nanometrics ca FAX To Support 1 613 592 5929 2 Trillium 240 OBS 15857R2 User Guide 2006 02 08 Installation This chapter provides an overview of installation and mass centring procedures for the Trillium 240 OBS Section 2 5 on page 6 provides a generic installation checklist 2 1 Unpacking the sensor Trillium 240 OBS is shipped in a very sturdy triple wall coated cardboard box with cus tom cut cushioning foam To minimize the possibility of damaging the sensor do not remove it from the box until it is ready to be placed in the pressure case K Save the shipping box and foam in case the sensor needs to be shipped again 2 2 Installing the sensor The Trillium 240 OBS is designed to be installed on a gimbal mounted platform in a pressure controlled bathysphere The Trillium 240 OBS has two sets of mounting fea tures to allow the sensor to be installed on either a plate with bosses or an annular ring K See Appendix F for information about the mounting and alignment features Do not exceed the maximum recommended torque value for the screw type and host material when installing the Trillium 240 OBS on your platform The Trillium 240 OBS base is aluminum For land based testing and setup of the Trillium 240 OBS you can use the optional Mounting Pedestal see Appendix E
24. l to obtain the low frequency broadband performance Short period mode is useful to see the mass positions respond quickly signals U_MP V_MP W_MP or the SOH lt Mass gt or lt ADC gt values when the sensor is being levelled In long period mode these numbers ramp very slowly and so care must be taken to not be misled by apparently centred values when in fact the sensor is not centred In short period mode these numbers respond within a second The sensor always powers up in long period mode Long period is the normal response for a 240 second lower corner frequency SetXYZ Set sensor to XYZ mode SetUVW Set sensor to UVW mode Use the Set XYZ and Set UVW commands to set the seismic output signals to the conventional XYZ horizontals and vertical mode or to the natural UVW mode in which the output of each axis is given directly XYZ mode is the default Note that this mode is also set by the UVW TX input line when the sensor is not in Serial Transmit mode The sensor responds to whichever command serial port or control line last signalled a change Center Center all masses or u v w You can use the Center command with or without parameters Without parameters Center initiates mass centring for all channels which can also be initiated by pulling the MC RX pin high for at least 1 sec ond referenced to DGND With a parameter u v or w Center will centre the specified axis without disturbing t
25. l values Units 0 z Zeroes 3 rad s n 108 161 0 01815 0 01799i 173 Pn Poles _196 231i rad s 732 1415i k Normalization factor 2 316 x 10 Osi Passband sensitivity at 1Hz 1196 5 V s m fo Normalization frequency 1 Hz 1 Trillium 240 OBS 15857R2 User Guide 2006 02 08 Chapter 3 Operation The transfer function is approximately flat out to 240s and rolls off at 40dB decade below the lower corner frequency as shown in Figure 3 2 Figure 3 2 Nominal frequency response Magnitude dB o ere i E Seismometer Calibration Combined Response L A RENS i ERES I ii 10 10 10 10 10 10 Frequency Hz 3 6 Self noise Typical Trillium 240 OBS self noise is plotted in Figure 3 3 Three curves are included for reference Peterson s new low noise model NLNM and new high noise model NHNM and McNamara and Buland s PDF Mode Low Noise Model MLNM The noise floor shown is the typical level of instrument self noise assuming proper instal lation 1 See also Peterson J 1993 Observations and Modeling of Seismic Background Noise Open file report 93 922 U S Geological Survey McNamara D E and R P Buland 1994 Ambient Noise Levels in the Continental United States Bull Seism Soc Am 94 1517 1527 Clinton J E and T H Heaton 2002 Potential Advantages of a Strong motion Velocity Meter over a Strong motion Accelerometer Seism Res Lett
26. n page 12 Sensitivity 1196 V s m 40 5 Bandwidth 3dB points are 244s and 207Hz Transfer function Lower corner poles within 0 5 of nominal provided High freguency poles and zeros within 5 of nominal provided Clip level 15mm s peak to peak differential up to 1 5Hz see also Figure 3 4 on page 13 Lower corner damping relative to critical 0 707 Output impedance 2 1500 1 Temperature 10 C without recentring Tilt Operational tilt range 1 Dynamic tilt Maximum tilt without recentring 0 03 Trillium 240 OBS 1 9 User Guide Appendix A Specifications A 3 Interface Connector 19 pin MIL C 26482 mounted on base Velocity output Selectable XYZ east north vertical or UVW mode 40V peak to peak differential Mass position output Three independent 4 5V outputs for UVW Calibration input Remote calibration in XYZ or UVW mode One voltage input for all channels Three separate control signals to enable U V or W channels Control inputs Isolated active high referenced to DGND Serial port RS 232 compatible For instrument control and retrieval of configuration information A 4 Power Supply voltage 9V to 36V DC isolated input Power consumption 650 mW typical at 15V input Protection Reverse voltage protected Self resetting over current protection No fuse to replace A 5 Physical Diameter 24 1cm Height 23 6cm includ
27. n to east Y north south Case motion to north Z vertical case motion upwards To select the sensor outputs gt To select the UVW outputs pull the UVW TX pin high To select the XYZ outputs either leave the UVW TX pin floating or set it to OV The sensor responds to changes on this control line within 4 seconds Note that this input control signal is disabled when the sensor is transmitting on the serial port since this pin is then used as the RS 232 serial TX output signal See Section 3 9 Connecting and configuring the serial port on page 14 To understand the difference between the UVW and XYZ outputs refer to Figure 3 1 The sensor axes have been designed so that they are identical and so that the directions in which they sense motion are orthogonal The U axis was chosen to be aligned with the East West axis when projected into the horizontal plane 8 Trillium 240 OBS 15857R2 User Guide 2006 02 08 Chapter 3 Operation Figure 3 1 Sensor axis orientations This arrangement results in the following transformation equations u 1 2 22 x x EQ 1 v 6 1 43 J2 y y 2 488 du a i 21 s EG KT 0 Ball EQ 2 2 A Pee ON 13 The first equation is implemented mechanically in the orientation of the Trillium 240 OBS individual sensor axes The second equation is implemented electronically when the Trillium 240 OBS is in XYZ mode Alternativ
28. nal pin D Be sure to take appropriate precautions for signal shielding and grounding to avoid introducing unwanted noise into the sensor or onto adjacent signal wires in the cable or the seismic signal from the sensor may become noisy 2 Setthe serial port on the communicating device to use this configuration e Speed 9600 baud Data Bits 8 e Parity None Stopbits 1 Flow Control Xon Xoff 3 If you are using a terminal emulator program enable these settings e Echo typed characters locally The Trillium 240 OBS serial port does not echo received characters on its transmit port e Send line ends with line feeds or equivalent The serial port expects all com mands to be terminated with the carriage return character ASCII OxOD 4 Once the sensor is powered up and an appropriate serial device connected as above send the characters Tx CR the CR denotes the carriage return char acter Note that the serial commands are not case sensitive Tx TX and t x are equivalent After a delay of 3 seconds the sensor will turn enable the UVW TX output and transmit Serial Transmit Enabled lt LF gt lt CR gt 5 To view help on the commands send the help command Help lt CR gt to get the sensor to transmit a help page displaying the various commands and syntax This is what would be displayed 14 Trillium 240 OBS 15857R2 User Guide 2006 02 08 Chapter 3 Operation Nanometrics Trillium
29. pability which facil itates both local and remote recentring Trillium seismometers have a symmetric triaxial arrangement of the sensing elements The use of three identical axis elements ensures the same frequency response for ver 15857R2 2006 02 08 Trillium 240 OBS 1 User Guide Chapter 1 Introduction tical and horizontal outputs is less susceptible to rapid changes in temperature and guarantees true orthogonality of the three outputs Data output of XYZ or UVW can be selected remotely allowing calibration of the ele ments independently of the electronics UVW data may also be used instead of XYZ for seismic signal recording if desired The Trillium 240 OBS is designed to be installed on a gimbal mounted platform in a pressure controlled bathysphere The Trillium 240 OBS case is designed to occupy a minimum volume and will not attenuate atmospheric pressure variations as well as the land based Trillium 240 To facilitate land based testing and setup of the Trillium 240 OBS an optional Mounting Pedestal is available which includes alignment markings adjustable locking levelling feet and a precision bubble level Please read the appropriate sections of this manual before transporting storing install ing or operating the Trillium 240 OBS If you need technical support please submit your request by email or fax Include a full explanation of the problem and supporting data to help us direct your request to the most
30. ptical limit switches This is measured and set at the factory for each axis The lt Positions gt number is the current position of the stepper motor rel ative to the midpoint of the total range A number close to zero means the mass positioning mechanism is near the midpoint of the range and has lots of room for further adjustment A positive or negative number close to half the lt Range gt number means the mass positioning mecha nism is near to the limit of its adjustment range The lt Zeros gt number is the position of the stepper motor which corre sponds to the sensor being level If the lt Position gt number is close to the lt Zeros gt number for all axes the sensor is close to nominally level The lt Zeros gt number is set at the factory for each axis 15857R2 Trillium 240 OBS 1 7 2006 02 08 User Guide Chapter 3 Operation Table 3 3 Serial port commands Continued Command Description ShortPer Set sensor to short period mode LongPer Set sensor to long period mode Use the ShortPer and LongPer commands to set the electronic mass centring response of the sensor to short period or to long period respectively Short period is used when mechanically recentring the masses and is automatically invoked when the mass recentring is initiated The prior mode is restored when mass centring completes Long period mode is the normal mode for collecting seismic data and is essentia
31. re loaded in the Trillium 240 OBS which can be the same version or different versions one loaded in partition A the other in partition B The sensor will run the firmware from the default partition on power up Use the Switch command to switch immediately to running the firmware in the other partition It does not change which partition is the default so that when the sensor is power cycled it will start up in the original default partition For example if the default partition is B and the Switch command is executed then partition A firmware is run immediately When the sensor is powered off and then on again it then switches back to running Partition B firmware K Use the CheckSum command to ensure there is valid code in both parti tions before switching Default Set the cur rent program as default Use the Default command to set the running firmware partition to be the default partition loaded at power up For example if the sensor is running partition A by default on power up to change to running partition B instead the procedure is 1 Execute the SOH command to verify that partition A is running 2 Use the Checksum command to verify that there is valid code in both par titions 3 Execute the Switch command to change to running partition B and the SOH command to verify that the new firmware is running 4 Execute the Default command to set partition B to be the default on power up Reboot Reboot the
32. ring llle m Ih 5 Continuous electronic mass recentring 0 000 eee eere 5 Mass recentring status c recce EL A 70 XE een 5 Mass centring procedure 2 222 s nennen tetas 5 Installation checklist 0 E R R ER T aA KNS EE ee 6 Operati Massieu als ee A Wink wearers ire paket iid a leds 7 Extemal c nnectors usa ar al UE ES ER ere Ace ea 7 Sensor POWER an a A A Rund E td ee 7 Control signals 3 2 A er ee a K 8 Output sigrials 1 dotes eroe le TR re eae TOA MT 8 Frequency response 0 0000 cee eee eee 10 SEIENOISE hen ee Mh nt D det ete oet e ee Lt e Rs 11 Calibration ssi are Yer d NINE SUUS Ca tut 13 States ASA aiii ee Paare ribs do eig Pare hs 14 Connecting and configuring the serial port llle eee 14 Troubleshooting and maintenance 000 eh 18 SPECHICAUOMS a uos aaa A dhe dann ea E ES 19 Technology jak t isto dtu pd doi bed da ee Lotes e ead 19 Performance ee ne A KN SRC ajat E 19 Interface sn er A ar nalen AR A DR 20 POWER NE A A AA A ADA 20 Physical zz ANA A a er M hm M ater Ba N E As 20 Environmental aas e ee ar Ba edo AA ae edi m dcs 20 Contents Connector PINOUT iu pr gere nee aba 21 Generic sensor Gabler run A S eed SPA 23 Cable Deslgri coe cet oth ce Ui Nee Ce ee DE UD ae 25 Trillium 240 OBS Mounting Pedestal 2222222 ernennen 27 Installing the Pedestal seor eere r ieh 200m R R d ee Re 27 kevellingitne ssemBly aadi malta as palm a en e 28 Al
33. s measuring true vertical motion 2 Trillium 240 OBS 15857R2 User Guide 2006 02 08 Appendix E Trillium 240 OBS Mounting Pedestal Figure E 1 Mounting the Trillium 240 OBS on the Pedestal 3 M6 SCREWS lt 15857R2 Trillium 240 OBS 29 2006 02 08 User Guide Appendix E Trillium 240 OBS Mounting Pedestal 3 Trillium 240 OBS 15857R2 User Guide 2006 02 08 Alignment and Mounting Features The Trillium 240 OBS is designed to be installed on a gimbal mounted platform in a pressure controlled bathysphere Figure F 1 shows the Trillium 240 OBS alignment features and features for mounting the sensor using either an annular ring or base posts See Appendix E for information on the optional Mounting Pedestal for land based testing and setup 15857R2 Trillium 240 OBS 31 2006 02 08 User Guide Appendix F Alignment and Mounting Features Figure F 1 Alignment and mounting features SIDE VIEW RING MOUNTING SURFACE RING MOUNTING HOLES 8X 11 40 2 137 BOTTOM VIEW 76 S 2a gt 15 3X M6x1 0 7mm DEEP 11 2 10 20 i 120 TYP 3X E 2b 32 Trillium 240 OBS 15857R2 User Guide 2006 02 08 Appendix F Alignment and Mounting Features Installation notes All dimensions are metric 1 Annular mounting ring installation a Minimum ring inside diameter to be 222 25mm 8 75 b Mounting holes to accommoda
34. te 8 32 socket cap head screws clearance diameter is 4 5mm for the screw and 7 9mm for the screw cap 2 3 post bottom installation This is the mounting method used by the optional mounting pedestal see also Appendix E The mounting platform is to have 3 posts or bosses of diameter 15mm and minimum height 2mm a 3 non painted spot surfaces where the post fixtures should be mounted using M6X1 0 screws b Minimum opening for the cable connector to be 45mm 15857R2 Trillium 240 OBS 33 2006 02 08 User Guide Appendix F Alignment and Mounting Features 34 Trillium 240 OBS 15857R2 User Guide 2006 02 08
35. tring feature For the Trident use options in the Nanometrics UI or use NaqsView 1 Install and level the Trillium 240 OBS as precisely as possible K For best results centre masses immediately after installing and levelling the Trillium 240 OBS and again at least 6 hours after installation when the temper 15857R2 2006 02 08 Trillium 240 OBS 5 User Guide Chapter 2 Installation ature has fully equalized This ensures the unit will then be able to tolerate up to 10 C range variation in ambient temperature without requiring recentring 2 Check the voltage readings on the mass position outputs for each of the three sen sor channels signals U MP V MP and W MB referenced to AGND to deter mine whether mass centring needs to be done Table 2 1 Table 2 1 Mass position output voltage indicating need for mass centring Mass position output voltage Need to centre the masses outside the range 3 5V yes within the range 3 5V but not within the range 2V strongly recommended within the range 2V but not within the range 0 3V recommended if it is convenient mass positions are all within the range 0 3V no although it can be done if desired 3 Initiate mass centring by pulling the MC RX pin high referenced to DGND pin R for at least 1 second This will initiate mass centring on all three axes in sequence first axis U then V then W The time for the operation to complete varies from a f
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